Infrapopliteal Anatomic Severity and Delayed Wound Healing in Patients With Chronic Limb-Threatening Ischemia in the Era of the Global Limb Anatomic Staging System

Purpose: To investigate the prognostic impact of infrapopliteal (IP) artery anatomic severity according to the Global Limb Anatomic Staging System (GLASS) on delayed wound healing in patients with chronic limb-threatening ischemia (CLTI). Materials and Methods: This study retrospectively analyzed 639 limbs with tissue loss in 484 CLTI patients (mean age 74±10 years; 300 men) presenting IP lesions treated with endovascular therapy between April 2010 and December 2015. Two-thirds of patients had diabetes (323, 67%) and over half were on hemodialysis (255, 53%). More than a third of the limbs (251, 39%) were classified as clinical stage 4 according to the Wound, Ischemia, and foot Infection (WIfI) system. IP anatomic severity was classified based on preprocedural angiography according to the GLASS. Severity of arterial calcification was assessed using high-intensity fluoroscopy and classified into 3 groups: none (grade 0), unilateral (grade 1), and bilateral (grade 2). Poor below-the-ankle (BTA) runoff was defined as the lack of a pedal arch with 0 to 1-vessel runoff within the dorsal pedis artery and the lateral and medial plantar arteries. The outcome measure was 1-year wound healing. The association of anatomic characteristics with delayed wound healing was evaluated using Cox proportional hazards regression analysis. Outcomes are presented as the adjusted hazard ratio (HR) with 95% confidence interval (CI). Results: During a mean follow-up of 22±19 months, the 1-year cumulative wound healing rate was estimated to be 59.0% (95% CI 54.5% to 63.5%). Multivariable analysis demonstrated independent associations between delayed wound healing and IP calcification grade (HR 1.24, 95% CI 1.02 to 1.50, p=0.027) and poor BTA runoff (HR 1.39, 95% CI 1.04 to 1.85, p=0.025) but not the GLASS IP grade (HR 0.92, 95% CI 0.82 to 1.14, p=0.21). Conclusion: The current study revealed that IP arterial calcification and poor BTA runoff were significantly associated with delayed wound healing, whereas the GLASS was not predictive of wound healing.